XXX what is the goal of af_switch()? it seems to me it is not necessary
any more with getaddrinfo(3) fix for correct name-resolution ordering.
comments? >shin
Sorry there were still several bugs.
-error retry at af missmatch was incomplete.
-af matching for source addr option was wrong
-socket was not freed at retry.
Approved by: jkh
-Should retry as much as possible when some of source
routing intermediate hosts' address families missmatch
happened.
(such as when a host has only A record, and another host
has each of A and AAAA record.)
-Should retry as much as possible when dest addr and
source addr(specified with -s option) address family
missmatch happend
Approved by: jkh
getnameinfo() don't return error at name resolving failure.
But it is used at doaddrlookup(-N) case in telnet, error need to be
returned to correctly initialize hostname buffer.
Discovered at checking recent KAME repository change, noticed by itojun.
Add some buffer overrun fixes from OpenBSD and myself.
Add skey calculator kludge from OpenBSD.
TODO: do a real merge of dab's sources... probably just make telnet and
telnetd contrib software.
Obtained from: OpenBSD, dab@bsdi.com
